Draft-regulating means



- ATTORNEYS Nov. 17, 1931.4 'o. sTARKE DRAFT REGULATING MEANS l Filed .July Vz3. 195o 5 @a Vm Patented Nov. 17, 1931 .UNiTED STATI-:s

PATENT oFFIcE o'r'ro sfuma, or BERLIN, GERMANY Appncmon 'mea July s, 1930, serial No. 466,518, and in Germany my 9, 1929.

The present invention vrelates to dampers for regulating or 'checking th'e f ,draft in the lues of sti'ves, furnaces, etc., and it is the object ofthe present invention to generally imBrove on 'contrivances of this kind. raft-regulating-means vhave already been roposed, in which the damper or slide mem- Eer forms in the closed position together with the frame a passage for the air which', up'on the closing movement, is caused to communicate with the atmosphere, and through which, in the case of, leakage or untight closure along Athe bearing faces of the damper, air is sucked up romthe atmosphere by reason of the draft prevailing in the chimney. These dampers,

however,`are accompanied by the disadvantage that the same form the air passage only on a part of the periphery of thegflue, sothat on the remaining part of the periphery the Adamper does not perform a suiliciently tight closure. Y

To overcome this disadvantage there is provided, according tothe invention,a hollow damper frame, which extendsover the'whole periphery of the cross-section of the iue, and which is open on the side directed towards the damperplate and is pressed against the same upon the closing movement by means of pressure rollers moving over wedge-like elevations thereon, while the hollow damper frame communicates with the atmosphere through the .medium of a pipe, the closure Hap of which, when the slide is open, is opened -1n positive fashion by the smoke slide upon its closing movement.

This arrangement has the advantage that the smoke slide according' to the invention may be used alone, and with the same'agreatly improved'eect is obtainable as compared with the arrangements hitherto usual. Alternatively, the new 'form of slide may be provided as a secondary slide behind an ordinary slide member, and in this case provides a much better closure of the `flue than two or dinary slides having an opening for the air c in front of or behind the second ordinary slide. v The invention will now be described more fully with reference `to the accompanying "drawings, which illustrate a possible form of embodiment by way of example.

-, Fig. 1 shows `the new slide in its applica-v tion to a boiler flue. g

Fig. 2 is -a section through the iiue, showing the slide, according to the lne 2-2 in Fig. 3. Fig. 3 is a section according to the line 3 3 in Fig. 2,

, Fig. 4 a section along the'line' in Fig.

I2, and

Fig. 5 an enlarged view of the air-inlet pipe.

Referring now to the drawings, the damper 'A 11, (F ig. 1) is iitted in the usual manner inthe iiue 12 between the boiler 1'3 and the chimney .14, and is connected by means of the rope' or cable 15 over rollers or pulleys 16.

with a counterweight 17. A A

In the flue 12, as shown in Figs. 2-4, there is provided for the damper or slide 11 a guide l and sealing frame 18, 'against 'which the slide 11 is somoved with the usual play between ledges 19 and 20 that the same is capable of responding to expansion by reason of heat. The frame 18 possesses about theA periphery a passage 21, which is opentowards the damper or slide 11. The slot 22 in the vtop 23 of the flue 12 is covered by the sheet metalfhousi'ng 24,.into which thefdamper passes in the openposition, so that .no false air is able to enter the ue. The damper or slide 11 possesses on the one side a number of wedge-shaped elevations 251 which, when the slide 11 is closed, pass over rollers 26 mounted on eccentrically ad- ]'ustable bolts 27 on the frame 18.V .In this manner the damper or slide 11 is in the closed position pressed irmly against the frame' 18, so that any leakage between the slide 11 andthe frame 18 is reduced to the lowest possible amount,

Since, however, the draft ofthe chimney v is still able to exert a slight eect'even on this minimized leakage, it is necessary to do away with the latter also. For this purpose there is connected to the passage 21 a pipe 28, which leads to the atmosphere, and .at

theupper end-it is closed by means of a iap 29. This flap possesses a lever 30, to

-which there is pivoted a rod 31 guided at 32 against the pipe 28. The rod 31 is furl nished at the lower end with a hook 33, which is capable of being engaged by anabutment or by the screw head 34 of the slide 1l.

When the slide is lowered the screw head 34, shortly before the closed position of the .slide is reached, moves against the hook 33 and 'conjointly moves the rod 3l, the flap 29 thus being opened. When, therefore, the damper or slide 11 is closed, air from the atmosphere is able to enter the passage 21 through the Hap 29 and the pipe 28, so that the draft in the chimney `is incapable of exerting any action on possible leakage between the frame 18 and damper 11, but sucks up air from the atmosphere.

Since the amounts of air sucked up by the chimneyy can only be very small, the air is preheated by the heat radiated by the boiler and the passages towards the damper, so that any appreciable cooling of the gas in the chimney is unable to occur even in the case of relatively long stationary periods.

Normally, the heat radiated by the boiler and the Hue will increase the temperature of the damper, causing it to expand. The arrangement according to the invention is thus accompanied by the additional advantage that this' heat, at least for thev greater part, is discharged through the lair way, or. is compensated thereby respectively, so that a warping or distortion of the damper will not take place, while at the same time the air passage will freely permit of any expansion which the damper may nevertheless .tend to undergo.

When the damper 11 is lifted, the wedgeshaped elevations 25 are released from the rollers 26, and the flap 29 =is closed, so that atmospheric air is no longer able to enter the Hue l2. V

It will'be understoodthat no restriction is made to the specific form of 'embodiment fshown in the' drawings, which is .quoted without departing from the spirit of the.7

invention.

What I 'claim as new and desire to secure by Letters Patent is:

l. In a draft-regulating means for furnaces, stoves and the like, a Hue, a damper in the said Hue, a hollow damper frame extending over the whole periphery of the crosssection of the Hue, an open passage in the 'said frame having the interrupted portion of its periphery directed towards'the said damper, a pipe connecting the said passage with atmosphere, a closure Hap to the said pipe, and means for positively opening the Ysaid Hap upon the closing movement of the said damper.

2. In a draft-regulating-means for furnaces, stoves and the like, a Hue, a damper in the said flue, a hollow damper frame extendto the said pipe, and means for ing over the whole periphery of the crosssection of the Hue, an open passage in the said frame having the interrupted portion of its periphery directed towards the said damper, a pipe connecting the said passage with atmosphere, means for tightly ressing the said damper against the said rame, a closure Hap to the said pipe, and means for positively opening the said Hap upon the closing movement of the said damper.

3. In a draft-regulating means for furnaces, stoves and the like, a Hue, a damper in the said Hue, a hollow damper frame extending over the whole periphery of the crosssection of the Hue, an open passage in the said frame Yhaving the interrupted portion of its periphery directed towards the said damper, apipe connecting the said passage with atmosphere, means for tightly pressing the said damper against the said frame, a closure flap to the said pipe, a lever on the said Hap, a hooked rod pivoted to the said lever, and an abutment on the said damper adapted to engage with the hook of the said rod for the purpose of positively openin the said Hap `upon the closing movement o the said damper.

4. In a draft-regulating means for furnaces, stoves and the like, a Hue, a damper in the said Hue,l a hollow damper frame extending over the whole periphery of the crosssection of the Hue, an open passage in the said frame having the interrupted portion of its periphery directed towards the said damper, a pipe connecting the said passage with atmosphere, wedge-shaped elevations on the one face of thev said.damp'er, rolls on the said frame 'adapted to be engaged bythe said 'elevations for tightly pressing the said damper against the said frame, a closure Hap positively opening the said Hap upon the closmg movement of the said damper.

5. In a form of embodiment of a draftvregulating means for furnaces, stoves and the like, a Hue, a damper in the said Hue, a hollow damper frameextending over the whole periphery of the cross-section of the Hue,` an open passage in the said frame havingthe interrupted portion of its periphery directed towards the said damper, a plpe connecting the said passage with atmosphere, wedgeshaped elevations on the one face of the saidv damper, rolls on the said frame adapted to be engaged by the said elevations, a closure Hap to. the said pipe, a lever on the said Hap, a hooked rod pivoted to the said lever, and an abutment on the said damper adapted to eugage with the hook of the said rod.

In testimony whereof I have aixed my signature.

` OTTO STARKE. 

